Recently, carbon nanotubes (CNTs) have attracted great attention in many research fields due to their superior mechanical, thermal and electrical properties. Although tremendous progress has been made in the synthesis of the CNTs, a major challenge remains in the search for an effective means to bridge the gap between the raw CNTs and the engineering materials/structures. In order to translate the superior properties of the CNTs to meso- or macro-scale structures, considerable efforts are being devoted to the development of CNT assemblies.